RFR: 8310974: NMT: Arena diffs miss the scale

[Aleksey Shipilev]

We noticed this in one of the NMT logs:


Compiler (reserved=175324KB +135838KB, committed=175324KB +135838KB)
    (malloc=29999KB +5558KB #23578 +8965)
    (arena=145325KB +130279 #17 -5)


The +130279 should actually be +130279KB. 

I looked at all current uses of `diff_in_current_scale` and `amount_in_current_scale`, and all them seem to be printed with scale. So we have only this one spot missing.

Note this also fixes the stray `d` leftover from [JDK-8281213](https://bugs.openjdk.org/browse/JDK-8281213).

Additional testing:
 - [x] macos-aarch64-server-fastdebug, `runtime/NMT`

-------------

Commit messages:
 - Fix the omission from JDK-8281213
 - Simpler form
 - Fix

Changes: https://git.openjdk.org/jdk/pull/14680/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14680&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8310974
  Stats: 3 lines in 1 file changed: 1 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/14680.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14680/head:pull/14680

PR: https://git.openjdk.org/jdk/pull/14680